Is it necessary to file a return?

Dear Sir,

A propreitor doing small Travel Agent business filed IT return for the AY 2010-11 eventhough there was no taxable income.

Subsequently failed to file IT returns for the AY 2011-12, 12-13 where there was no taxable income. 

As there was a taxable income during the  AY 2013-14 the belated return has been filed recently.

Pls. let me know Is it mandatory to file the return for the previous years A Y 11-12 & 12-13?    

or submitting the compliance form in the efiling portion stating "no taxable income" is enough.